drm: Add helpers for setting up an array of dma_fence dependencies. (5d5a179d) · Commits · 戴 / test

drivers/gpu/drm/drm_gem.c

+93 −0

Original line number	Diff line number	Diff line
		@@ -1367,3 +1367,96 @@ drm_gem_unlock_reservations(struct drm_gem_object **objs, int count,
		ww_acquire_fini(acquire_ctx);
		}
		EXPORT_SYMBOL(drm_gem_unlock_reservations);

		/**
		* drm_gem_fence_array_add - Adds the fence to an array of fences to be
		* waited on, deduplicating fences from the same context.
		*
		* @fence_array array of dma_fence * for the job to block on.
		* @fence the dma_fence to add to the list of dependencies.
		*
		* Returns:
		* 0 on success, or an error on failing to expand the array.
		*/
		int drm_gem_fence_array_add(struct xarray *fence_array,
		struct dma_fence *fence)
		{
		struct dma_fence *entry;
		unsigned long index;
		u32 id = 0;
		int ret;

		if (!fence)
		return 0;

		/* Deduplicate if we already depend on a fence from the same context.
		* This lets the size of the array of deps scale with the number of
		* engines involved, rather than the number of BOs.
		*/
		xa_for_each(fence_array, index, entry) {
		if (entry->context != fence->context)
		continue;

		if (dma_fence_is_later(fence, entry)) {
		dma_fence_put(entry);
		xa_store(fence_array, index, fence, GFP_KERNEL);
		} else {
		dma_fence_put(fence);
		}
		return 0;
		}

		ret = xa_alloc(fence_array, &id, fence, xa_limit_32b, GFP_KERNEL);
		if (ret != 0)
		dma_fence_put(fence);

		return ret;
		}
		EXPORT_SYMBOL(drm_gem_fence_array_add);

		/**
		* drm_gem_fence_array_add_implicit - Adds the implicit dependencies tracked
		* in the GEM object's reservation object to an array of dma_fences for use in
		* scheduling a rendering job.
		*
		* This should be called after drm_gem_lock_reservations() on your array of
		* GEM objects used in the job but before updating the reservations with your
		* own fences.
		*
		* @fence_array array of dma_fence * for the job to block on.
		* @obj the gem object to add new dependencies from.
		* @write whether the job might write the object (so we need to depend on
		* shared fences in the reservation object).
		*/
		int drm_gem_fence_array_add_implicit(struct xarray *fence_array,
		struct drm_gem_object *obj,
		bool write)
		{
		int ret;
		struct dma_fence **fences;
		unsigned int i, fence_count;

		if (!write) {
		struct dma_fence *fence =
		reservation_object_get_excl_rcu(obj->resv);

		return drm_gem_fence_array_add(fence_array, fence);
		}

		ret = reservation_object_get_fences_rcu(obj->resv, NULL,
		&fence_count, &fences);
		if (ret \|\| !fence_count)
		return ret;

		for (i = 0; i < fence_count; i++) {
		ret = drm_gem_fence_array_add(fence_array, fences[i]);
		if (ret)
		break;
		}

		for (; i < fence_count; i++)
		dma_fence_put(fences[i]);
		kfree(fences);
		return ret;
		}
		EXPORT_SYMBOL(drm_gem_fence_array_add_implicit);

include/drm/drm_gem.h

+5 −0

Original line number	Diff line number	Diff line
		@@ -390,6 +390,11 @@ int drm_gem_lock_reservations(struct drm_gem_object **objs, int count,
		struct ww_acquire_ctx *acquire_ctx);
		void drm_gem_unlock_reservations(struct drm_gem_object **objs, int count,
		struct ww_acquire_ctx *acquire_ctx);
		int drm_gem_fence_array_add(struct xarray *fence_array,
		struct dma_fence *fence);
		int drm_gem_fence_array_add_implicit(struct xarray *fence_array,
		struct drm_gem_object *obj,
		bool write);
		int drm_gem_dumb_map_offset(struct drm_file file, struct drm_device dev,
		u32 handle, u64 *offset);
		int drm_gem_dumb_destroy(struct drm_file *file,

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